Chemical Quality and Antibacterial Activity of Lutjanus Dentatus (Dumeril, 1860) Oils as a Function of Extraction Method

Abstract Background: The limits of antibiotic prompted researchers to explore foods components as antimicrobial. The present study was initiated to value the oils extracted from the fat tissues of Lutjanus dentatus against food poisoning bacteria.Methods: The oils were extracted from the adipose tissue by drying at 45°C for 24 hours and by cooking in a pressure cooker at 95°C for 20 minutes followed by pressing. Subsequently, the oil extraction yield and the chemical characterization from quality indices according to standard methods and physical analysis by Fourier transform infrared (FTIR) spectroscopy were evaluated. The oils antibacterial activity, their emulsion as well as their interactions with some common antibiotics were evaluated by the broth microdilution method.Results: L. dentatus oil adipose tissue extraction yield obtained by cooking at 95oC was high (66.83%) compared to that obtained after drying at 45oC (55.50%). The oil extracted from L. dentatus adipose tissue by drying at 45oC showed peroxide (9.76±1.19 meqd’O2) and anisidine indices (40.94±0.8) higher than those obtained by cooking at 95°C (6.56±0.40 meq d’O2 and 37.85±0.34 respectively). However, the acid, iodine and thiobarbituric acid value of oils extracted using the two methods were not significantly different P≤0.05. The FTIR profile provided information on the functional groups present in the oil and enable to appreciate the variation of the peaks compared to the quality indicesThe antibacterial test showed that the oils studied all had antibacterial activity. The best spectrum of action (23/23 bacteria tested 16 ≤ MIC ≤ 256 mg / ml) was noted with the oil extracted by cooking at 95oC. Regardless of the extraction method, emulsions have better antibacterial activity compared to the oils (0.39 ≤ MIC ≤ 12.5 mg/ml). Moreover L. dentatus oil adipose tissue potentiated the activity of Ciprofloxacin, Tetracyclin, Gentamicin, Amoxicilin and Chloramphenicol on the bacterial strains tested.Conclusion: These results are a source of motivation for a much more in-depth exploration of the antimicrobial properties of the L. dentatus oil.